feat: Refactoring to pass an option object to initialize hooks more e…

…xplicitly (#7)

packages/hooks/src/base.ts

@@ -15,7 +15,7 @@ export function registerMiddleware<T> (target: T, middleware: Middleware[]) {
   return target;
 }
 
-export function getMiddleware (target: any): Middleware[] {
+export function getMiddleware<T> (target: any): Array<Middleware<T>> {
   return (target && target[HOOKS]) || [];
 }
 
@@ -39,6 +39,39 @@ export class HookContext<T = any, C = any> {
  * arguments of the function call.
  */
 export type ContextUpdater<T = any> = (self: any, args: any[], context: HookContext<T>) => HookContext<T>;
+/**
+ * A function that for a given function, calling context and arguments returns the list of hooks
+ */
+export type MiddlewareCollector<T = any> = (self: any, fn: any, args: any[]) => Array<Middleware<T>>;
+
+/**
+ * Available options when initializing hooks with more than just an array of middleware
+ */
+export interface FunctionHookOptions<T = any> {
+  middleware: Array<Middleware<T>>;
+  context: ContextUpdater<T>;
+  collect: MiddlewareCollector<T>;
+}
+
+export type HookSettings<T = any> = Array<Middleware<T>>|Partial<FunctionHookOptions>;
+
+export function defaultCollectMiddleware<T = any> (self: any, fn: any, _args: any[]) {
+  return [
+    ...getMiddleware<T>(self),
+    ...getMiddleware(fn)
+  ];
+}
+
+export function normalizeOptions<T = any> (opts: HookSettings): FunctionHookOptions<T> {
+  const options: Partial<FunctionHookOptions> = Array.isArray(opts) ? { middleware: opts } : opts;
+  const {
+    middleware = [],
+    context = withParams(),
+    collect = defaultCollectMiddleware
+  } = options;
+
+  return { middleware, context, collect };
+}
 
 /**
  * Returns a ContextUpdater function that turns function arguments like

packages/hooks/src/decorator.ts

@@ -1,15 +1,12 @@
-import { Middleware } from './compose';
 import { functionHooks } from './function';
-import { ContextUpdater, withParams, HookContext, registerMiddleware } from './base';
+import { HookContext, registerMiddleware, normalizeOptions, HookSettings } from './base';
 
-export const hookDecorator = <T> (hooks: Array<Middleware<T>>, _updateContext?: ContextUpdater<T>) => {
+export const hookDecorator = <T> (hooks: HookSettings<T> = []) => {
   return (_target: any, method: string, descriptor: TypedPropertyDescriptor<any>): TypedPropertyDescriptor<any> => {
-    if (!descriptor) {
-      if (_updateContext) {
-        throw new Error('Context can not be updated at the class decorator level. Remove updateContext parameter.');
-      }
+    const options = normalizeOptions(hooks);
 
-      registerMiddleware(_target.prototype, hooks);
+    if (!descriptor) {
+      registerMiddleware(_target.prototype, options.middleware);
 
       return _target;
     }
@@ -20,16 +17,19 @@ export const hookDecorator = <T> (hooks: Array<Middleware<T>>, _updateContext?:
       throw new Error(`Can not apply hooks. '${method}' is not a function`);
     }
 
-    const originalUpdateContext = _updateContext || withParams();
-    const updateContext = (self: any, args: any[], context: HookContext<any>) => {
-      const ctx = originalUpdateContext(self, args, context);
+    const originalContext = options.context;
+    const context = (self: any, args: any[], context: HookContext<any>) => {
+      const ctx = originalContext(self, args, context);
 
       ctx.method = method;
 
       return ctx;
     };
 
-    descriptor.value = functionHooks(fn, hooks, updateContext);
+    descriptor.value = functionHooks(fn, {
+      ...options,
+      context
+    });
 
     return descriptor;
   };

packages/hooks/src/function.ts

@@ -1,8 +1,5 @@
 import { compose, Middleware } from './compose';
-import {
-  HookContext, ContextUpdater, withParams,
-  registerMiddleware, getMiddleware
-} from './base';
+import { HookContext, registerMiddleware, normalizeOptions, HookSettings } from './base';
 
 /**
  * Returns a new function that is wrapped in the given hooks.
@@ -11,20 +8,16 @@ import {
  * just set `context.arguments` to the function call arguments
  * and `context.self` to the function call `this` reference.
  *
- * @param fn The function to wrap
- * @param hooks The list of hooks (middleware)
- * @param updateContext A ContextUpdate method
+ * @param original The function to wrap
+ * @param options A list of hooks (middleware) or options for more detailed hook processing
  */
-export const functionHooks = <T = any>(
-  fn: any,
-  hooks: Array<Middleware<T>>,
-  updateContext: ContextUpdater = withParams()
-) => {
-  if (typeof fn !== 'function') {
+export const functionHooks = <F, T = any>(original: F, opts: HookSettings<T>) => {
+  if (typeof original !== 'function') {
     throw new Error('Can not apply hooks to non-function');
   }
 
-  const result = registerMiddleware(function (this: any, ...args: any[]) {
+  const { context: updateContext, collect, middleware } = normalizeOptions(opts);
+  const wrapper = function (this: any, ...args: any[]) {
     // If we got passed an existing HookContext instance, we want to return it as well
     const returnContext = args[args.length - 1] instanceof HookContext;
     // Initialize the context. Either the default context or the one that was passed
@@ -35,14 +28,12 @@ export const functionHooks = <T = any>(
     const hookChain: Middleware[] = [
       // Return `ctx.result` or the context
       (ctx, next) => next().then(() => returnContext ? ctx : ctx.result),
-      // The hooks attached to the `this` object
-      ...getMiddleware(this),
-      // The hook chain attached to this function
-      ...getMiddleware(result),
+      // Create the hook chain by calling the `collectMiddleware function
+      ...collect(this, wrapper, args),
       // Runs the actual original method if `ctx.result` is not already set
       (ctx, next) => {
         if (ctx.result === undefined) {
-          return Promise.resolve(fn.apply(this, ctx.arguments)).then(result => {
+          return Promise.resolve(original.apply(this, ctx.arguments)).then(result => {
             ctx.result = result;
 
             return next();
@@ -54,7 +45,9 @@ export const functionHooks = <T = any>(
     ];
 
     return compose(hookChain).call(this, context);
-  }, hooks);
+  };
 
-  return Object.assign(result, { original: fn });
+  registerMiddleware(wrapper, middleware);
+
+  return Object.assign(wrapper, { original });
 };